On densely packed printed circuit boards, a means for transferring heat away from electronic components is needed. The traditional means for cooling electronic components such as integrated circuit packages is to use convection air currents to carry off the excess heat. Typically, fins are either integrally formed as part of the component package or are separately attached to the component package. The fins increase the surface area of the component package to improve transfer of excess heat to convection air currents. Cooling is further improved by the use of a fan to increase the volume of air available for cooling.
It has usually been assumed that to cool an electronic component, the majority of heat produced by the component must be radiated to convection air from the surface of the component package. Therefore, most attempts to improve the cooling of electronic components have focused on improving the transfer of excess heat from the package to convection air currents.
As is known, however, many electronic components, such as integrated circuit packages, have pins which attach the components to a printed circuit board The board separates and supports the components and connects the components to form an electronic circuit. The pins of the components pass through the printed circuit board and are soldered to the board on the back side of the board opposite to the mounted components. Although the pins are a thermally-conductive path from the heat-producing parts of the component, transfer of heat from the component through the pins to convection air is normally inefficient because of the small surface area of the pins exposed to convection air.